1. Technical Field
This invention relates to large eccentric fittings that are used on walking mechanisms of drag line excavators which are used to move the immense size and weight of the current excavators in use.
2. Description of Prior Art
Prior art eccentrics of this type are typically cast given the nature of the load forces at work in moving modern massive drag line excavators by using a walking mechanism in which a pair of parallel spaced support shoe assemblies selectively and cyclically support the excavator as it is raised and moved forward incrementally. Improved drag line walking mechanisms can be seen for example in U.S. Pat. Nos. 3,500,945, 3,901,341 and 5,603,174.
U.S. Pat. No. 3,500,945 discloses a walking mechanism assembly with a walking crank with inboard and outboard support using an eccentrically board walking arm.
U.S. Pat. No. 3,901,341 claims a tractor mechanism for a walking drag line excavator with moving feet by radial disk cam and crank engagement of each respective foot.
U.S. Pat. No. 5,603,174 is directed to an improved walking mechanism for a drag line excavator in which a transmission output shaft drives an eccentric within the walking leg housing.